Supplemental Cash Flow Disclosures (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
	Jan. 01, 2019	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Cash paid during the period for:
Interest				$ 1,314	$ 1,946
Income taxes				0	3,790
Noncash investing activities:
Unrealized gain on unrecognized post retirement costs		$ 20	$ 14	40	28
Unrealized gain on available for sale securities		952	275	827	563
Unrealized loss on junior subordinated debentures		$ (1,208)	$ (542)	(453)	(1,247)
Cash dividend declared				1,866	$ 1,865
Adoption of ASU 2016-02: recognition of lease right-of-use (ROU) asset	$ 3,395			$ 0
Adoption of ASU 2016-02: recognition of lease liability	$ 3,486
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201602Member